Clock Modes - Synchronization - RME Audio MADIface USB User Manual

Clock Mode
Sample Rate
Used to set the current sample rate. This is the same setting as in the Audio MIDI Setup, just
added here for your convenience.
At ongoing record/playback the selection is greyed out, so no change is possible.
Clock Source
The unit can be configured to use its own clock (Internal = master), or one of the input signals. If
the selected source isn't available, the unit will change to the next available one (AutoSync). If
none is available then the internal clock is used. The Current Clock source is shown below.
Input Status
Indicates for each input whether there is a valid signal (Lock, No Lock), or if there is a valid and
synchronous signal (Sync). The second row shows the sample frequency measured by the
hardware. The third and fourth row shows the input's channel format (48k/96k Frame, 64 or 56
channels). The BNC input supports the formats MADI coaxial, AES and word.

14.2 Clock Modes - Synchronization

In the digital world, all devices must be either Master (clock source) or Slave (clock receiver).
Whenever several devices are linked there must always be a single master clock.
A digital system can only have one master! If the MADIface's clock mode is set to 'Internal',
all other devices must be set to 'Slave'.
The MADIface USB utilizes a very user-friendly, intelligent clock control, called AutoSync. In
AutoSync mode, the system constantly scans all digital inputs for a valid signal. If any valid sig-
nal is found, the MADIface switches from the internal quartz (Clock Mode – Current Internal) to
a clock extracted from the input signal (Clock Mode – Current Optical, Coaxial, AES or Word).
The difference to a usual slave mode is that whenever the clock reference fails, the system will
automatically use its internal clock and operate in Master mode.
The MADIface USB inputs operate simultaneously. Because there is no input selector in some
modes, the MADIface USB has to be told which one of the signals is the sync reference - a
digital device can only be clocked from a single source. The Clock Source selection is used to
define a preferred input for the automatic clock system. This input will stay active as long as a
valid signal is found.
To cope with some situations which may arise in studio practice, defining a sync reference is
essential. RME's exclusive SyncCheck technology (first implemented in the Hammerfall) en-
ables an easy to use check and display of the current clock status. Input Status indicates
whether there is a valid signal (Lock, No Lock) for each input, or if there is a valid and synchro-
nous signal (Sync). In the field Clock Mode the clock reference is shown (Current...). See chap-
ter 26.2.
In practice, SyncCheck provides the user with an easy way of checking whether all digital de-
vices connected to the system are properly configured. With SyncCheck, finally anyone can
master this common source of error, previously one of the most complex issues in the digital
studio world.
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User's Guide MADIface USB © RME